/*	$OpenBSD: chmod.c,v 1.43 2018/09/16 02:44:06 millert Exp $	*/
/*	$NetBSD: chmod.c,v 1.12 1995/03/21 09:02:09 cgd Exp $	*/

/*
 * Copyright (c) 1989, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include <sys/types.h>
#include <sys/stat.h>

#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <fts.h>
#include <grp.h>
#include <limits.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "compat.h"

int ischown, ischgrp, ischmod;

gid_t a_gid(const char *);
uid_t a_uid(const char *, int);
static void usage(void);

int main(int argc, char *argv[]) {
  setprogname(argv[0]);
  FTS *ftsp;
  FTSENT *p;
  void *set;
  unsigned long val;
  int oct;
  mode_t omode;
  int Hflag, Lflag, Rflag, ch, fflag, fts_options, hflag, rval, atflags;
  uid_t uid;
  gid_t gid;
  u_int32_t fclear, fset;
  char *ep, *mode, *cp, *flags;

  if (strlen(__progname) > 2) {
    ischown = __progname[2] == 'o';
    ischgrp = __progname[2] == 'g';
    ischmod = __progname[2] == 'm';
  }

  uid = (uid_t)-1;
  gid = (gid_t)-1;
  Hflag = Lflag = Rflag = fflag = hflag = 0;
  while ((ch = getopt(argc, argv, "HLPRXfghorstuwx")) != -1)
    switch (ch) {
    case 'H':
      Hflag = 1;
      Lflag = 0;
      break;
    case 'L':
      Lflag = 1;
      Hflag = 0;
      break;
    case 'P':
      Hflag = Lflag = 0;
      break;
    case 'R':
      Rflag = 1;
      break;
    case 'f': /* no longer documented. */
      fflag = 1;
      break;
    case 'h':
      hflag = 1;
      break;
    /*
     * If this is a symbolic mode argument rather than
     * an option, we are done with option processing.
     */
    case 'g':
    case 'o':
    case 'r':
    case 's':
    case 't':
    case 'u':
    case 'w':
    case 'X':
    case 'x':
      if (!ischmod)
        usage();
      /*
       * If getopt() moved past the argument, back up.
       * If the argument contains option letters before
       * mode letters, setmode() will catch them.
       */
      if (optind > 1) {
        cp = argv[optind - 1];
        if (cp[strlen(cp) - 1] == ch)
          --optind;
      }
      goto done;
    default:
      usage();
    }
done:
  argv += optind;
  argc -= optind;

  if (argc < 2)
    usage();

  /*
   * We alter the symlink itself if doing -h or -RP, or
   * if doing -RH and the symlink wasn't a command line arg.
   */
  atflags = AT_SYMLINK_NOFOLLOW;

  fts_options = FTS_PHYSICAL;
  if (Rflag) {
    if (hflag)
      errx(1, "the -R and -h options may not be specified together.");
    if (Hflag)
      fts_options |= FTS_COMFOLLOW;
    if (Lflag) {
      fts_options &= ~FTS_PHYSICAL;
      fts_options |= FTS_LOGICAL;
      atflags = 0;
    }
  } else if (!hflag) {
    fts_options |= FTS_COMFOLLOW;
    atflags = 0;
  }

  if (ischmod) {
    mode = *argv;
    if (*mode >= '0' && *mode <= '7') {
      errno = 0;
      val = strtoul(mode, &ep, 8);
      if (val > INT_MAX)
        errno = ERANGE;
      if (errno)
        err(1, "invalid file mode: %s", mode);
      if (*ep)
        errx(1, "invalid file mode: %s", mode);
      omode = val;
      oct = 1;
    } else {
      if ((set = setmode(mode)) == NULL)
        errx(1, "invalid file mode: %s", mode);
      oct = 0;
    }
  } else if (ischown) {
    /* Both UID and GID are given. */
    if ((cp = strchr(*argv, ':')) != NULL) {
      *cp++ = '\0';
      gid = a_gid(cp);
    }
    /*
     * UID and GID are separated by a dot and UID exists.
     * required for backwards compatibility pre-dating POSIX.2
     * likely to stay here forever
     */
    else if ((cp = strchr(*argv, '.')) != NULL &&
             (uid = a_uid(*argv, 1)) == (uid_t)-1) {
      *cp++ = '\0';
      gid = a_gid(cp);
    }
    if (uid == (uid_t)-1)
      uid = a_uid(*argv, 0);
  } else
    gid = a_gid(*argv);

  if ((ftsp = fts_open(++argv, fts_options, 0)) == NULL)
    err(1, NULL);
  for (rval = 0; (p = fts_read(ftsp)) != NULL;) {
    switch (p->fts_info) {
    case FTS_D:
      if (!Rflag)
        fts_set(ftsp, p, FTS_SKIP);
      if (ischmod)
        break;
      else
        continue;
    case FTS_DNR: /* Warn, chmod, continue. */
      errno = p->fts_errno;
      warn("%s", p->fts_path);
      rval = 1;
      break;
    case FTS_DP: /* Already changed at FTS_D. */
      if (ischmod)
        continue;
      else
        break;
    case FTS_ERR: /* Warn, continue. */
    case FTS_NS:
      errno = p->fts_errno;
      warn("%s", p->fts_path);
      rval = 1;
      continue;
    case FTS_SL: /* Ignore. */
    case FTS_SLNONE:
      /*
       * The only symlinks that end up here are ones that
       * don't point to anything or that loop and ones
       * that we found doing a physical walk.
       */
      if (!hflag && (fts_options & FTS_LOGICAL))
        continue;
      break;
    default:
      break;
    }

    /*
     * For -RH, the decision of how to handle symlinks depends
     * on the level: follow it iff it's a command line arg.
     */
    if (fts_options & FTS_COMFOLLOW) {
      atflags = p->fts_level == FTS_ROOTLEVEL ? 0 : AT_SYMLINK_NOFOLLOW;
    }

    if (ischmod) {
      if (!fchmodat(AT_FDCWD, p->fts_accpath,
                    oct ? omode : getmode(set, p->fts_statp->st_mode),
                    atflags) ||
          fflag)
        continue;
    } else if (ischown) {
      if (!fchownat(AT_FDCWD, p->fts_accpath, uid, gid, atflags) || fflag)
        continue;
    }

    /* error case */
    warn("%s", p->fts_path);
    rval = 1;
  }
  if (errno)
    err(1, "fts_read");
  fts_close(ftsp);
  return (rval);
}

/*
 * Given a UID or user name in a string, return the UID.  If an empty string
 * was given, returns -1.  If silent is 0, exits on invalid user names/UIDs;
 * otherwise, returns -1.
 */
uid_t a_uid(const char *s, int silent) {
  const char *errstr;
  uid_t uid;

  if (*s == '\0') /* Argument was "[:.]gid". */
    return ((uid_t)-1);

  /* User name was given. */
  if (uid_from_user(s, &uid) != -1)
    return (uid);

  /* UID was given. */
  uid = (uid_t)strtonum(s, 0, INT_MAX, &errstr);
  if (errstr) {
    if (silent)
      return ((uid_t)-1);
    else
      errx(1, "user is %s: %s", errstr, s);
  }

  return (uid);
}

/*
 * Given a GID or group name in a string, return the GID.  If an empty string
 * was given, returns -1.  Exits on invalid user names/UIDs.
 */
gid_t a_gid(const char *s) {
  const char *errstr;
  gid_t gid;

  if (*s == '\0') /* Argument was "uid[:.]". */
    return ((gid_t)-1);

  /* Group name was given. */
  if (gid_from_group(s, &gid) != -1)
    return (gid);

  /* GID was given. */
  gid = (gid_t)strtonum(s, 0, INT_MAX, &errstr);
  if (errstr)
    errx(1, "group is %s: %s", errstr, s);

  return (gid);
}

static void usage(void) {
  fprintf(stderr, "usage: %s [-h] [-R [-H | -L | -P]] %s file ...\n",
          __progname,
          ischmod   ? "mode"
          : ischown ? "owner[:group]"
                    : "group");
  if (ischown)
    fprintf(stderr, "       %s [-h] [-R [-H | -L | -P]] :group file ...\n",
            __progname);
  exit(1);
}
